No. 4S9] 



THE STRUCTUh'H OF (ILIA 



others who consider that the isolated cihum is ciipahle 

 but hicks onk the necessary stimuhis. 



^riiat the core or axis of the cihnni is alwav 

 iT-nprol)able bv the tact that many psemloi)cdia and tl 

 of the Siictoria, which are admittedly homolouou. with c 

 haye a central canal or a fluid core (Imo-. 2, m. Ah 

 experiments of Zacharias ^ who caused the s[)ennatu/(. 

 phemus to produce slender ciha-hke pseudopodia by 

 them in a 5 per cent, solution of sodium phosphate, ; 

 wazek ^ who saw the retracting protoplasm of an mjuu-d 

 of Siphonaea brijopsis produce in h\e minutes (iha wh 

 the rate of 40 strokes a minute, and who ' also toiind in CI 

 ciha appearing as small processes ^^inch in 8 nnnu 

 halt then normal si/e and beat 10 time, m 20 stcon.K 

 ceitdin ciha must consist of but slightK modihul i 

 These experiments also indicate that a solid or a pern 

 i« not always formed, for in the first two cases the cilia w- 

 dt.tuncd Ttis(h 11 tint 1 tnbi (ontiiniii^ i fluid 

 escape either becausi- ol tlu ( t il tui;;(»i oi iHiau i ( 



tube ^Mll a(t piidMh 



